The Neuroendocrine Assay Core will provide the UCLA Women's Health and Functional Visceral Disorders Center with state of the art resources and expertise related to the measurement of neuroendocrine mediators involved in central and peripheral signaling pathways and interpretation of results. The Core will have the capability to perform radioimmunoassay, HPLC, and MDLC measurement of serum and CSF levels of neuroendocrine mediators in samples obtained from human and animal subjects. The Neuroendocrine Assay Core will be directed by Dr. Gordon V. Ohning, MD, PhD and co-directed by Dr. Joseph Reeve, Jr., Ph.D. The Core will utilize much of the existing equipment and resources that are available in the NIH-funded CURE: Digestive Diseases Research Center/ Antibody and Radioimmunoassay Core (G. Ohning, P.I.) and Peptide Biochemistry and Molecular Probes Core laboratories (J. Reeve, P.L). Dr. Ohning has formal training in Internal Medicine, Gastroenterology and in the Postdoctoral Research Training Program in Psychiatry and Biobehavioral Sciences. He has considerable experience in radioimmunoassay techniques and ELISA measurements. He has also had a longstanding clinical research interest in functional GI disorders and has collaborated with the P.I. in this area. Dr. Reeve has over 25 years of experience in protein chemistry and purification techniques and expertise in HPLC and Multi-Dimensional Liquid Chromatography (MDLC). He has considerable research experience in isolation, purification, and identification of bioactive peptides and non-peptide transmitters. Peter Chew, M.S. will be the primary technician responsible for the RIA, HPLC, and MDLC techniques required to perform the assays within the scope of the Core services. He has over 25 years of experience with these techniques and will coordinate efforts with the Core Co-Directors and Investigators utilizing the Core Services, including quality control of all procedures and development of new methods for assay. The Director, Co-Director and Primary Technician will work together as a team to provide a cohesive and efficient Core that will not only provide analysis of neuroendocrine samples, but also provide consultation on the correct methods for obtaining and processing samples and the interpretation of results. The Core Laboratory will also provide training as part of the Career Development Program, and participate at all levels in Center operations.